Method and system for actively defending a wireless LAN against attacks

ABSTRACT

A wireless network security system including a system data store capable of storing network default and configuration data, a wireless transmitter and a system processor. The system processor performs a network security method. An active defense request signal is received, typically from an intrusion detection system. The received request signal includes an indicator of an access point within the wireless computer network that is potentially compromised. In response to the received an active defense of the wireless network is triggered. The triggered active defense may be on or more of transmitting a jamming signal, transmitting a signal to introduce CRC errors, transmitting a signal to increase the difficulty associated with breaking the network encryption (typically by including in the signal packet appearing legitimate but containing randomized payloads, or transmitting a channel change request to the potentially compromised access point.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application claims the benefit, pursuant to 35 U.S.C. §119(e), ofapplicant's provisional U.S. Patent Application Ser. No. 60/381,829,filed May 20, 2002, entitled “SYSTEMS AND METHODS FOR NETWORK SECURITY”,which application is hereby incorporated by this reference in itsentirety for all purposes.

This application is related to the following U.S. Patent Applicationsfiled Jun. 3, 2002, each of which is hereby incorporated by thisreference in its entirety for all purposes:

Attorney Serial Docket No. Inventors Title Number 19282.0001U2 Hrastar,“SYSTEMS AND TBA Lynn, METHODS FOR NET- Sale, WORK SECURITY”Hollingsworth 19282.0002U1 Hrastar “SYSTEM AND METHOD TBA FOR WIRELESSLAN DYNAMIC CHANNEL CHANGE WITH HONEY- POT TRAP” 19282.0005U1 Hrastar,“METHODS AND TBA Lynn SYSTEMS FOR IDENTI- FYING NODES AND MAPPING THEIRLOCA- TIONS” 19282.0006U1 Hrastar “METHOD AND SYSTEM TBA FOR ENCRYPTEDNET- WORK MANAGE- MENT AND INTRUSION DETECTION”

BACKGROUND

The present invention is directed to systems and methods for enhancingsecurity associated with electronic communications. More specifically,without limitation, the present invention relates to computer-basedsystems and methods for assessing security risks and identifying andresponding to threats in wireless network environments.

The Internet is a global network of connected computer networks. Overthe last several years, the Internet has grown in significant measure. Alarge number of computers on the Internet provide information in variousforms. Anyone with a computer connected to the Internet can potentiallytap into this vast pool of information.

The information available via the Internet encompasses informationavailable via a variety of types of application layer informationservers such as SMTP (simple mail transfer protocol), POP3 (Post OfficeProtocol), GOPHER (RFC 1436), WAIS, HTTP (Hypertext Transfer Protocol,RFC 2616) and FTP (file transfer protocol, RFC 1123).

One of the most wide spread method of providing information over theInternet is via the World Wide Web (the Web). The Web consists of asubset of the computers connected to the Internet; the computers in thissubset run Hypertext Transfer Protocol (HTTP) servers (Web servers).Several extensions and modifications to HTTP have been proposedincluding, for example, an extension framework (RFC 2774) andauthentication (RFC 2617). Information on the Internet can be accessedthrough the use of a Uniform Resource Identifier (URI, RFC 2396). A URIuniquely specifies the location of a particular piece of information onthe Internet. A URI will typically be composed of several components.The first component typically designates the protocol by which theaddress piece of information is accessed (e.g., HTTP, GOPHER, etc.).This first component is separated from the remainder of the URI by acolon (‘:’). The remainder of the URI will depend upon the protocolcomponent. Typically, the remainder designates a computer on theInternet by name, or by IP number, as well as a more specificdesignation of the location of the resource on the designated computer.For instance, a typical URI for an HTTP resource might be:

http://www.server.com/dir1/dir2/resource.htm

where http is the protocol, www.server.com is the designated computerand /dir1/dir2/resouce.htm designates the location of the resource onthe designated computer. The term URI includes Uniform Resource Names(URN's) including URN's as defined according to RFC 2141.

Web servers host information in the form of Web pages; collectively theserver and the information hosted are referred to as a Web site. Asignificant number of Web pages are encoded using the Hypertext MarkupLanguage (HTML) although other encodings using eXtensible MarkupLanguage (XML) or XHTML. The published specifications for theselanguages are incorporated by reference herein; such specifications areavailable from the World Wide Web Consortium and its Web site(http://www.w3c.org). Web pages in these formatting languages mayinclude links to other Web pages on the same Web site or another. Aswill be known to those skilled in the art, Web pages may be generateddynamically by a server by integrating a variety of elements into aformatted page prior to transmission to a Web client. Web servers, andinformation servers of other types, await requests for the informationfrom Internet clients.

Client software has evolved that allows users of computers connected tothe Internet to access this information. Advanced clients such asNetscape's Navigator and Microsoft's Internet Explorer allow users toaccess software provided via a variety of information servers in aunified client environment. Typically, such client software is referredto as browser software.

Electronic mail (e-mail) is another wide spread application using theInternet. A variety of protocols are often used for e-mail transmission,delivery and processing including SMTP and POP3 as discussed above.These protocols refer, respectively, to standards for communicatinge-mail messages between servers and for server-client communicationrelated to e-mail messages. These protocols are defined respectively inparticular RFC's (Request for Comments) promulgated by the IETF(Internet Engineering Task Force). The SMTP protocol is defined in RFC821, and the POP3 protocol is defined in RFC 1939.

Since the inception of these standards, various needs have evolved inthe field of e-mail leading to the development of further standardsincluding enhancements or additional protocols. For instance, variousenhancements have evolved to the SMTP standards leading to the evolutionof extended SMTP. Examples of extensions may be seen in (1) RFC 1869that defines a framework for extending the SMTP service by defining ameans whereby a server SMTP can inform a client SMTP as to the serviceextensions it supports and in (2) RFC 1891 that defines an extension tothe SMTP service, which allows an SMTP client to specify (a) thatdelivery status notifications (DSNs) should be generated under certainconditions, (b) whether such notifications should return the contents ofthe message, and (c) additional information, to be returned with a DSN,that allows the sender to identify both the recipient(s) for which theDSN was issued, and the transaction in which the original message wassent.

In addition, the IMAP protocol has evolved as an alternative to POP3that supports more advanced interactions between e-mail servers andclients. This protocol is described in RFC 2060.

The various standards discussed herein by reference to particular RFC'sare hereby incorporated by reference herein for all purposes. TheseRFC's are available to the public through the Internet Engineering TaskForce (IETF) and can be retrieved from its Web site(http://www.ietf.org/rfc.html). The specified protocols are not intendedto be limited to the specific RFC's quoted herein above but are intendedto include extensions and revisions thereto. Such extensions and/orrevisions may or may not be encompassed by current and/or future RFC's.

A host of e-mail server and client products have been developed in orderto foster e-mail communication over the Internet. E-mail server softwareincludes such products as sendmail-based servers, Microsoft Exchange,Lotus Notes Server, and Novell GroupWise; sendmail-based servers referto a number of variations of servers originally based upon the sendmailprogram developed for the UNIX operating systems. A large number ofe-mail clients have also been developed that allow a user to retrieveand view e-mail messages from a server; example products includeMicrosoft Outlook, Microsoft Outlook Express, Netscape Messenger, andEudora. In addition, some e-mail servers, or e-mail servers inconjunction with a Web server, allow a Web browser to act as an e-mailclient using the HTTP standard.

As the Internet has become more widely used, it has also created newrisks for corporations. Breaches of computer security by hackers andintruders and the potential for compromising sensitive corporateinformation are a very real and serious threat.

Wireless Local Area Networks (WLANs) offer a quick and effectiveextension of a wired network or standard local area network (LAN). FIG.1 depicts a typical LAN 190 including both wired and wirelesscomponents. The wired component depicted in FIG. 1 includes a variety ofconnected systems including local servers 120, local clients 130 andnetwork accessible data storage components 110. By simply installingaccess points 180A, 180B to the wired network (e.g., Ethernet 150 androuter 140), personal computers and laptops equipped with WLAN cards170A, 170B can connect with the wired network at broadband speeds.

Over the last few years, most deployments of WLANs have conformed to theInstitute of Electrical and Electronics Engineers (IEEE) 802.11bstandard that operates over the unregulated 2.4 GHz frequency spectrum.The 802.11b standard offers connectivity of up to 11 Mbps—fast enough tohandle large e-mail attachments and run bandwidth-intensive applicationslike video conferencing. While the 802.11 b standard now dominates theWLAN market, other variations of the 802.11 standard, such as 802.11 a,802.11g, and 802.1X, are being developed to handle increased speeds.WLAN vendors have committed to supporting a variety of standards. Thevarious 802.11 standards developed by the IEEE are available fordownload via URL: http://standards.ieee.org/getieee802/802.11.html;these various standards are hereby incorporated by this referenceherein.

As businesses connected their LANs to the Internet 160, they installedfirewalls 145 to protect their local networks and act as security gatesto fend off unauthorized traffic coming from the Internet's informationhighway such as potential hacker 135. The mobility of air-bound,wireless networks creates security concerns where threats can come fromany direction and are not limited to the wired infrastructure.Established security practices of guarding a few wired entry points tothe network are no longer effective. A firewall 145 may effectivelydeter an attack from a wired hacker 135 via the Internet 160; however,wireless hackers 195A, 195B typically enter the LAN 190 through accesspoints 180A, 180B that are already behind the firewall 145. Companiesmust constantly monitor their airwaves to survey wireless activity andguard against intruders.

Because wireless communication is broadcast over radio waves,eavesdroppers 195A, 195B who merely listen to the airwaves can easilypick up unencrypted messages. Additionally, messages encrypted with theWired Equivalent Privacy (WEP) security protocol can be decrypted with alittle time and easily available hacking tools. These passive intrudersput businesses at risk of exposing sensitive information to corporateespionage.

The theft of an authorized user's identity poses one the greatestthreats. Service Set Identifiers (SSIDs) that act as crude passwords andMedia Access Control (MAC) addresses that act as personal identificationnumbers are often used to verify that clients are authorized to connectwith an access point. However, existing encryption standards are notfoolproof and allow knowledgeable intruders to pick up approved SSIDsand MAC addresses to connect to a WLAN as an authorized user with theability to steal bandwidth, corrupt or download files, and wreak havocon the entire network.

Outsiders who cannot gain access to a WLAN can none-the-less posesecurity threats by jamming or flooding the airwaves with static noisethat causes WLAN signals to collide and produce CRC errors. TheseDenial-of-Service (DoS) attacks effectively shut down the wirelessnetwork in a similar way that DoS attacks affect wired networks.

Careless and deceitful actions by both loyal and disgruntled employeesalso present security risks and performance issues to wireless networkswith unauthorized access points, improper security measures, and networkabuses. Because a simple WLAN can be easily installed by attaching a$150 access point to a wired network and a $100 WLAN card to a laptop,employees are deploying unauthorized WLANs or peer-to-peer wirelessconnections 175 when IT departments are slow to adopt the newtechnology.

Incorrectly configured access points are an avoidable but significanthole in WLAN security. Many access points are initially configured tobroadcast unencrypted SSIDs of authorized users. While SSIDs areintended to be passwords to verify authorized users, intruders caneasily steal an unencrypted SSID to assume the identity of an authorizeduser.

Authorized users can also threaten the integrity of the network withabuses that drain connection speeds, consume bandwidth, and hinder aWLAN's overall performance. A few users who clog the network by tradinglarge files such as MP3 audio or MPEG video files can affect theproductivity of everyone on the wireless network.

The systems and methods according to the present invention providesolutions to these and other security and/or management issuesassociated with WLANs and/or encrypted computer networks.

SUMMARY

The present invention is directed to systems and methods for enhancingnetwork security. One preferred embodiment according to the presentinvention includes a system data store (SDS), a system processor and oneor more interfaces to one or more communications channels which mayinclude one or more interfaces to wireless and/or encryptedcommunications network over which electronic communications aretransmitted and received. The SDS stores data needed to provide thedesired system functionality and may include, for example, receivedcommunications, data associated with such communications, informationrelated to known security risks and predetermined responses to theidentification of particular security risks and situations. The SDS mayinclude multiple physical and/or logical data stores for storing thevarious types of information. Data storage and retrieval functionalitymay be provided by either the system processor or data storageprocessors associated with the data store.

The system processor is in communication with the SDS via any suitablecommunication channel(s); the system processor is in communication withthe one or more interfaces via the same, or differing, communicationchannel(s). The system processor may include one or more processingelements that provide electronic communication reception, transmission,interrogation, analysis and/or other functionality.

Each interface to a wireless network includes at least one receiveradapted to receive wireless communications; each interface may also, orinstead, include one or more transmitters adapted to transmit wirelesscommunications. Each interface to a wired network, if any, include areceiver, a transmitter, both or a plurality of one and/or both; suchreceivers and/or transmitters are adapted to receive or transmitcommunication over the wired network to which the interface connects. Inone preferred embodiment, the communication interface includes at leastone wireless transmitter.

Accordingly, one preferred method of security enhancement includes avariety of steps that may, in certain embodiments, be executed by theenvironment summarized above and more fully described below or be storedas computer executable instructions in and/or on any suitablecombination of computer-readable media. An active defense request signalis received. The active defense request signal includes an indicatorcorresponding to an access point within the wireless computer networkthat is potentially compromised by an intruder. In response to thereceived signal, one or more active defense are triggered. In somepreferred embodiments, the active defenses include jamming, CRC errorgeneration, random frame transmission, network lock-down and/or dynamicchannel change.

In some embodiments supporting dynamic channel change, a honeypot trapvariation can be included. In such embodiments, a honeypot trap may beactivated culminating in a channel change request to the potentiallycompromised access point. Configuration data associated with an accesspoint on a wireless computer network potentially compromised by anintruder is received. Information contained within and/or derived fromthe received configuration data is stored. Communication with theintruder is continued by emulating the identification characteristics ofthe potentially compromised access point. In some embodiments,communication may appear to come from an access point that appears lesssecure than the potentially compromised access point. A channel changerequest is transmitted to the potentially compromised access point toreroute communication between the potentially compromised access pointand authorized stations may continue to a different channel.

In some embodiments, the active defense request signal is received froman intrusion detection system such as described in greater detail below.In such embodiments, the indicator of the potentially compromised accesspoint can be included as part of a generated active defense requestsignal. In other instances, an alarm signal is received that triggersthe generation and transmission of a request for information regardingthe potentially compromised access point. Some embodiments involving anintrusion detection system may include the intrusion detection systemwhile others just respond to input from such a system.

Some embodiments further include the mapping of the identification ofthe intruder's node and/or the mapping of the location of the intruder'snode within the wireless network. In some instances, a notification ofthe triggering of the active defense can be sent to an administrator;some such notifications may include an identification and/or location ofthe node associated with the intruder in embodiments that include nodeidentification and location mapping.

In some embodiments, the configuration data includes one or more riskcriteria, network default data, network policy, performance and/or usagedata. This configuration information may be received from one or more ofa variety of sources including from a configuration file, an interactivedata entry interface or a command line or from monitoring the wirelesscomputer network.

Some embodiments may further include updating of various types of storedinformation; different embodiment may update all, none or anycombination of the various types of stored information. For instance,some embodiments can update station information associated with thevarious stations in the wireless computer network based upon thereceived data. Further, some embodiments can update state informationregarding the security of the wireless computer network based upon thereceived data. In addition, some embodiments can update statistics basedupon the received data. Such updates can occur each time data isreceived, in response to reaching a fixed amount of such update data, inresponse to reaching a fixed time or the end of a predeterminedduration, or some combination of these approaches.

Additional advantages of the invention will be set forth in part in thedescription which follows, and in part will be obvious from thedescription, or may be learned by practice of the invention. Theadvantages of the invention will be realized and attained by means ofthe elements and combinations particularly pointed out in the appendedclaims. It is to be understood that both the foregoing generaldescription and the following detailed description are exemplary andexplanatory only and are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description, serve to explain the principles of theinvention.

FIG. 1 graphically depicts a typical LAN with both wired and wirelesscomponents.

FIGS. 2A–E graphically depicts LANs incorporating various preferredembodiments according to the present invention.

FIG. 3 is a flow chart of a multi-dimensional wireless intrusiondetection process according to one preferred embodiment of the presentinvention.

FIG. 4 is a flow chart of an example multiple input wireless intrusiondetection process including multiple input correlation and long-termdata fusion.

FIG. 5 is a flow chart of an exemplary dynamic channel change activedefense process that includes a honeypot trap.

FIGS. 6A–B are flow charts of example station identification andlocation mapping processes.

DETAILED DESCRIPTION

Exemplary embodiments of the present invention are now described indetail. Referring to the drawings, like numbers indicate like partsthroughout the views. As used in the description herein and throughoutthe claims that follow, the meaning of “a,” “an,” and “the” includesplural reference unless the context clearly dictates otherwise. Also, asused in the description herein and throughout the claims that follow,the meaning of “in” includes “in” and “on” unless the context clearlydictates otherwise. Finally, as used in the description herein andthroughout the claims that follow, the meanings of “and” and “or”include both the conjunctive and disjunctive and may be usedinterchangeably unless the context clearly dictates otherwise; thephrase “exclusive or” may be used to indicate situation where only thedisjunctive meaning may apply.

Ranges may be expressed herein as from “about” one particular value,and/or to “about” another particular value. When such a range isexpressed, another embodiment includes from the one particular valueand/or to the other particular value. Similarly, when values areexpressed as approximations, by use of the antecedent “about,” it willbe understood that the particular value forms another embodiment. Itwill be further understood that the endpoints of each of the ranges aresignificant both in relation to the other endpoint, and independently ofthe other endpoint.

The term “Wi-Fi” is short for wireless fidelity and is another name forIEEE 802.11b. The foregoing discussion of exemplary embodiments may useterminology or make reference to the IEEE 802.11b standard, or other802.11 variant; however, those skilled in the art will appreciate thatsystems and methods of the present invention may be applied to WLANsmeeting these standards as well as WLANs developed according tocompeting WLAN standards. The phrase “frame” as used herein shall meanbroadly any discretely defined communication transmitted via a computernetwork and shall not be limited to those specific frame types (control,management, data and error) defined according to 802.11X standards.

Architecture of a Typical Access Environment

FIGS. 2A–E depicts several LAN environments including several preferredembodiments according to the present invention. These figures depict atypical LAN environment as depicted in FIG. 1 having wired and wirelesscomponents. In contrast to FIG. 1, FIGS. 2A–E include one or morehardware components supporting preferred embodiments according to thepresent invention. The depicted hardware components include a systemprocessor, an SDS and one or more interfaces to one or more wirelessand/or encrypted communications network over which electroniccommunications are transmitted and received.

The hardware components depicted in these figures are outlined asfollows:

In FIG. 2A, the hardware components include a single device 210A thatincludes the a local processor serving as the system processor and theone or more interfaces to the wireless network. The device 210A ispreferably a mobile computer system such as a notebook computer. Thelocal primary and/or secondary storage of device 210A may serve as theSDS; alternatively, portions of the SDS may be provided by other systemscapable of communicating with the device 210A such as networkaddressable data storage 110, local servers 120 and/or wireless stations170A, 170B. In some embodiments, the device's interfaces to the wirelessnetwork may be limited to one or more wireless receivers. In otherembodiments, the interfaces may include one or more wirelesstransmitters as well as one or more transmitters. If wirelesstransmitters are included, the device 210 may communicate over LAN 190using a wireless access point 180A, 180B. In addition, included wirelesstransmitters may be used to support one or more of the active defensemeasures described in greater detail below. In some embodiments, thedevice 210A may further include a wired connection (not shown) toEthernet 150 allowing direct communication between it and systemsconnected to the wired portion of LAN 190.

In FIG. 2B, the hardware components include multiple devices 210A, 210B,210C, 210D. Each device 210A–D includes a local processor and one ormore interfaces to the wireless network and is preferably a mobilecomputer system such as a notebook computer. The individual localprocessors in the aggregate serve as the system processor. The SDS mayinclude a combination of storage local to each of the devices and/orexternal storage accessible via the LAN 190. As described above withrespect to FIG. 2A, each device includes at least a wireless receiverbut may also include additional wireless receivers and/or wirelesstransmitters. Each device may also include a wired connection (notshown) to Ethernet 150. Finally, the devices 210A–D may further useexisting interfaces and/or incorporate additional interfaces to allowpeer-to-peer communication among themselves.

In FIG. 2C, the hardware components include multiple devices 210A, 210B,210C, 210D, 220. Each device 210A–D may include the various componentsas described above with respect to FIG. 2B. Device 220 includes a localprocessor and one or more communication interfaces; this device may bereferred to hereinafter as the host system. Device 220's communicationinterfaces may include only a wired communication interface and mayreceive data related to wireless communications as forwarded by devices210A–D over the wire Ethernet 150. In addition to, or instead of, thewired communication interface, device 220 may include a one or morewireless communication interfaces each of which may include a wirelessreceiver, a wireless transmitter or both. In embodiment where devices210A–D support peer-to-peer communication, device 220 may in some ofsuch embodiments participate in the peer-to-peer communication and, insuch instances, its communication interfaces would include theappropriate communication interface to support this participation. Thesystem processor functionality in the depicted embodiment may beprovided by the host system alone and/or by some combination of thedevices 210A–D. The host system may in some embodiments provide the SDSfor the environment; alternatively, the SDS may be supported by somecombination of the local storage among the devices 210A–D, the localstorage in the host system and external storage available through LAN190.

-   -   In FIG. 2D, the hardware components include multiple devices        210A, 210B, 210C, 210D, 220, 230A, 230B. Devices 210A–D, 220        support the same functionality and include the same range of        components as provided above with respect to FIG. 2C. In        addition, devices 230A, 230B are sensor devices that monitor        wireless traffic over the wireless network. These sensor devices        at least include a wireless receiver for monitoring the traffic        and a communication interface wired (as depicted) or wireless        (not shown) allowing communication with one or more of the        devices 210A–D and/or the host system 220. In some embodiments,        the sensor devices 230A, 230B may include a wireless transmitter        for supporting communication with the other hardware components        and/or for supporting various active wireless network defensive        measures as discussed below. In some embodiments, the sensor        device 230A, 230B may further include local processing        capability and or local storage capability; in some such        embodiments, the system processor and/or the SDS may incorporate        these local capabilities of the sensor devices 230A, 230B.    -   In FIG. 2E, the hardware components include multiple devices        220, 230A, 230B. In this embodiment, the host system 220 and        sensor devices 230A, 230B include the same functionality and        range of components as discussed above with respect to FIGS. 2D        and 2E respectively. In such embodiments, the host system 220        will typically provide a significant portion of the system        processor functionality and will only have limited capacity to        directly receive wireless network communication. In some of        these embodiments, the host system 220 may have no wireless        communication interface.

The depicted hardware components include a system processor potentiallyincluding multiple processing elements, that may be distributed acrossthe depicted hardware components, where each processing element may besupported via Intel-compatible processor platforms preferably using atleast one PENTIUM III or CELERON (Intel Corp., Santa Clara, Calif.)class processor; alternative processors such as UltraSPARC (SunMicrosystems, Palo Alto, Calif.) could be used in other embodiments. Insome embodiments, security enhancement functionality, as furtherdescribed below, may be distributed across multiple processing elements.The term processing element may refer to (1) a process running on aparticular piece, or across particular pieces, of hardware, (2) aparticular piece of hardware, or either (1) or (2) as the contextallows. The sensor devices 230A, 230B depicted in FIGS. 2D–E may in somepreferred embodiments include more limited optimized local processorssuch as a digital signal processor (DSP). Other embodiment can useapplication specific integrated circuits (ASIC) or a field programmablegate arrays (FPGA).

The depicted hardware components include an SDS that could include avariety of primary and secondary storage elements. In one preferredembodiment, the SDS would include RAM as part of the primary storage;the amount of RAM might range from 64 MB to 4 GB in each individualhardware device although these amounts could vary and representoverlapping use such as where the host system 220 supports additionalfunctionality such as integrated with firewall system 145 for providingunified wired and wireless security. The primary storage may in someembodiments include other forms of memory such as cache memory,registers, non-volatile memory (e.g., FLASH, ROM, EPROM, etc.), etc. Thesensor devices 230A, 230B depicted in FIGS. 2D–E may in some preferredembodiments include more limited amounts and kinds of primary storage.In one preferred embodiments, the primary storage in the sensor devicesincludes FLASH memory.

The SDS may also include secondary storage including single, multipleand/or varied servers and storage elements. For example, the SDS may useinternal storage devices connected to the system processor. Inembodiments where a single processing element supports all of thesecurity analysis functionality, such as seen in FIGS. 2A and 2E, alocal hard disk drive may serve as the secondary storage of the SDS, anda disk operating system executing on such a single processing elementmay act as a data server receiving and servicing data requests.

It will be understood by those skilled in the art that the differentinformation used in the security enhancement processes and systemsaccording to the present invention may be logically or physicallysegregated within a single device serving as secondary storage for theSDS; multiple related data stores accessible through a unifiedmanagement system, which together serve as the SDS; or multipleindependent data stores individually accessible through disparatemanagement systems, which may in some embodiments be collectively viewedas the SDS. The various storage elements that comprise the physicalarchitecture of the SDS may be centrally located, or distributed acrossa variety of diverse locations.

The architecture of the secondary storage of the system data store mayvary significantly in different embodiments. In several embodiments,database(s) are used to store and manipulate the data; in some suchembodiments, one or more relational database management systems, such asDB2 (IBM, White Plains, N.Y.), SQL Server (Microsoft, Redmond, Wash.),ACCESS (Microsoft, Redmond, Wash.), ORACLE 8i (Oracle Corp., RedwoodShores, Calif.), Ingres (Computer Associates, Islandia, N.Y.), MySQL(MySQL AB, Sweden) or Adaptive Server Enterprise (Sybase Inc.,Emeryville, Calif.), may be used in connection with a variety of storagedevices/file servers that may include one or more standard magneticand/or optical disk drives using any appropriate interface including,without limitation, IDE and SCSI. In some embodiments, a tape librarysuch as Exabyte X80 (Exabyte Corporation, Boulder, Colo.), a storageattached network (SAN) solution such as available from (EMC, Inc.,Hopkinton, Mass.), a network attached storage (NAS) solution such as aNetApp Filer 740 (Network Appliances, Sunnyvale, Calif.), orcombinations thereof may be used. In other embodiments, the data storemay use database systems with other architectures such asobject-oriented, spatial, object-relational or hierarchical.

Instead of, or in addition to, those organization approaches discussedabove, certain embodiments may use other storage implementations such ashash tables or flat files or combinations of such architectures. Suchalternative approaches may use data servers other than databasemanagement systems such as a hash table look-up server, procedure and/orprocess and/or a flat file retrieval server, procedure and/or process.Further, the SDS may use a combination of any of such approaches inorganizing its secondary storage architecture.

The hardware components may each have an appropriate operating systemsuch as WINDOWS/NT, WINDOWS 2000 or WINDOWS/XP Server (Microsoft,Redmond, Wash.), Solaris (Sun Microsystems, Palo Alto, Calif.), or LINUX(or other UNIX variant). In one preferred embodiment, the devices 210A–Dand/or host system 220 include a LINUX (or other UNIX variant) operatingsystem; although other embodiments may include a WINDOWS/XP (or otherWINDOWS family) operating system.

Depending upon the hardware/operating system platform of the overallenvironment, appropriate server software may be included to support thedesired access for the purpose of configuration, monitoring and/orreporting. Web server functionality may be provided via an InternetInformation Server (Microsoft, Redmond, Wash.), an Apache HTTP Server(Apache Software Foundation, Forest Hill, Md.), an iPlanet Web Server(iPlanet E-Commerce Solutions—A Sun—Netscape Alliance, Mountain View,Calif.) or other suitable Web server platform. The e-mail services maybe supported via an Exchange Server (Microsoft, Redmond, Wash.),sendmail or other suitable e-mail server. Some embodiments may includeone or more automated voice response (AVR) systems that are in additionto, or instead of, the aforementioned access servers. Such an AVR systemcould support a purely voice/telephone driven interface to theenvironment with hard copy output delivered electronically to suitablehard copy output device (e.g., printer, facsimile, etc.), and forward asnecessary through regular mail, courier, inter-office mail, facsimile orother suitable forwarding approach.

In one preferred embodiment, devices 210A–D and host system 220 can beconfigured locally or remotely, and configuration can occur through aninteractive interface and/or through a command line interface. Theinteractive interface is accessible locally whereas the command lineinterface is accessible either locally or remotely. Remote access ispreferably granted through the use of a secure shell (SSH) clientcommunicating with an SSH server running on the device or host system.

In some preferred embodiments of the present invention, an interactiveinterface is provided for configuring the access point and varioushardware components and supplying a variety of configuration dataincluding thresholds values of various kinds. In one preferredembodiment, an administration program area provides such an interfaceand allows:

-   -   definition and configuration of access point settings and        policies;    -   creation and/or designation of thresholds used to trigger        intrusion/detection alarms for authorized access points;    -   creation and/or designation of default thresholds used to        trigger intrusion/detection alarms for non-authorized access        points; and    -   configuration of settings for the various hardware/software        components.

The administration program area, in one preferred embodiment, offersstandard windowing interface featuring tabbed pages for easy navigationbetween configuration functions. From within each of the tabbed pages,an Edit button allows modification of the values. After editing thedata, Accept temporarily saves the changes. Commit permanently saves andapplies edits (until edited again). Accepted changes persist until thesystem is restarted whereas committed changes persist until acrossrestarts.

Access Point Configuration

One preferred embodiment automatically attempts to detect and record allthe configured properties for all access points it observes. Thesettings constitute access point “policies”—when access point propertiesdeviate from those recorded, one or more alarms can be generated. Thevalues for an access point can be modified manually to alter thegeneration of specific alarms. Policies for off-line access points canalso be created in some embodiments using an Add feature.

The table below provides a summary of several access point propertiesdisplayable and/or configurable in some preferred embodiments of thepresent invention.

Values Description Access Point ID The MAC address of the access point.Access Point Name The user-defined name of the access point. ExtendedService The name of the Extended Service Set indicating Set ID thewireless network to which the access point belongs. Access Point Themanufacturer of the access point. In some em- Vendor bodiments, this isdetected by comparing the first three bytes of its MAC address with adatabase of OUI numbers. Supported Rates The data transfer rates theaccess point supports. In some embodiments, this value (or these values)can be edited to specify the supported rates. Authentication Whether theaccess point accepts non-authenticated Modes network connections and/oralso accepts shared key authentication. (If connections are detectedthat deviate from either of these settings, an alarm can be generated.)Configured to Run Whether or not the access point is configured to re-WEP quire WEP encryption. AP Mgmt From Whether the access point isconfigured to allow Wireless Network users to directly administer itssettings over the wireless network. Authorized Access Whether thisaccess point is authorized to be present Point in the air space.Unauthorized access points, when detected, can generate alarms. (In someembodi- ment, a change in this value will not take effect until thesystem is restarted.)

For each access point, a station maintenance screen or menu may allowthe specification of the stations that are authorized to use it. Onepreferred embodiment of such a screen or menu, automatically detects allstations within the footprint of the access point's Basic Service Set(BSS) and enters their MAC addresses in an Observed column. Suchstations can be indicated as an authorized member of the BSS byselecting them in the Observed column and designating them as Valid.Designated stations are moved to a Valid column. (Stations can, in someembodiments, be designated as invalid by selecting and marking them inthe Valid column.) Stations not auto-detected can be manually entered byspecifying its MAC address in a Enter New Station input field andtriggering an Add Station feature.

Access Point Threshold Configuration and Aggregate Station Thresholds

Systems and methods according to the present invention generate alertsif network traffic that exceeds thresholds is detected. In one preferredembodiment, all detected or manually configured off-line access pointsare listed in a Select AP pick list. Thresholds associated with eachaccess point in the pick list can be edited by selecting the particularaccess point. Such threshold values can be either temporary (until thenext restart) or persistent across restarts (until a further editdesignated as persistent).

Values Description Signal Strength If the signal strength for anystation in the BSS is Threshold lower than this value, an alarm can begenerated. # of Associations Enter the maximum number of associationsper minute per Minute to allow with all stations combined. (Preferably,this value is not higher than twice the number of stations in the BSS.)# of Associated Enter the maximum number of stations allowed to Stationsassociate at any one time with this access point. The number shouldreflect the actual number of stations. If a greater number is detected,an alarm can be generated.

The following table outlines a set of thresholds used in one preferredembodiment that refer to the network characteristics encompassing allstations and traffic in the BSS. In one preferred embodiment, specialcare must be taken when creating the “byte thresholds” that immediatelyfollow. Several factors govern the values entered for each:

-   -   The “transmission rate” of the access point—how much data it can        transmit—is the first consideration. If the transmission rate is        only 1 megabyte per second, the thresholds will be much lower        than if the transmission rate is 11 megabytes per second.

All four “directions” of traffic (wired to wired, wired to wireless,wireless to wired, and wireless to wireless) must add up to less than100% of available bandwidth. Many administrators will set the individualthresholds such that their combined value is less than 80% of availablebandwidth.

Value Description # Bytes into Enter the maximum number of bytes of dataper minute BSS from allowed into the BSS from the wired portion of yourWired Net network. If a greater number is detected, an alarm can begenerated. # Bytes from Enter the maximum number of bytes of data perminute BSS to Wired allowed out of the BSS to a wired portion of yourNet network. If a greater number is detected, an alarm can be generated.# Bytes Enter the maximum number of bytes of data per minute betweenallowed to be transmitted within the BSS from all sta- Stations intions. If a greater number is detected, an alarm can be BSS generated. #Bytes from Enter the maximum number of bytes of data per minute WiredNet to allowed to be transmitted from a wired portion of the Wired Netnetwork to another wired portion of the network, using the access pointas a bridge. If a greater number is de- tected, an alarm can begenerated. Total Data Enter the maximum number of data frames per minuteFrames Seen from all stations combined allowed to be transmitted. If agreater number is detected, an alarm can be generated. Total Mgmt Enterthe maximum number of management frames per Frames Seen minute from allstations combined allowed to be trans- mitted. If a greater number isdetected, an alarm can be generated. Total Ctrl Enter the maximum numberof control frames per minute Frames Seen from all stations combinedallowed to be transmitted. If a greater number is detected, an alarm canbe generated. Total Ad hoc Enter the maximum number of ad hoc frames perminute Frames Seen from all stations combined allowed to be transmitted.If a greater number is detected, an alarm can be generated.Individual Station Thresholds

The following table outlines a set of potential thresholds applied toany individual station in one preferred embodiment. If any singlestation reaches one of these thresholds, an alarm can be generated.

Column Description Signal Strength If the signal strength for anystation in the BSS is Threshold lower than this value, an alarm can begenerated. # of Associations Enter the maximum number of associationsper min- per Minute ute any station is allowed to make with an accesspoint. If a greater number is detected, an alarm can be generated. # ofBytes Enter the maximum number of bytes of data per Transmitted minuteany station is allowed transmit. If a greater number is detected, analarm can be generated. # of Bytes Enter the maximum number of bytes ofdata per Received minute any station is allowed to receive. If a greaternumber is detected, an alarm can be generated. # of Data Frames Enterthe maximum number of data frames per min- Transmitted ute any stationis allowed to transmit. If a greater number is detected, an alarm can begenerated. # of Data Frames Enter the maximum number of data frames permin- Received ute any station is allowed to receive. If a greater numberis detected, an alarm can be generated. # of Mgmt Frames Enter themaximum number of management frames Transmitted per minute any stationis allowed to transmit. If a greater number is detected, an alarm can begener- ated. # of Mgmt Frames Enter the maximum number of managementframes Received per minute any station is allowed to receive. If agreater number is detected, an alarm can be gener- ated. # of CtrlFrames Enter the maximum number of control frames per Transmitted minuteany station is allowed to transmit. If a greater number is detected, analarm can be gener- ated. # of Ctrl Frames Enter the maximum number ofcontrol frames per Received minute any station is allowed to receive. Ifa greater number is detected, an alarm can be generated. # of FragmentEnter the maximum number of fragment frames per Frames Seen minute fromany station that are allowed. If a greater number is detected, an alarmcan be generated. # of Decrypt Error Enter the maximum number of decrypterror frames Frames Seen per minute from any station that are allowed.If a greater number is detected, an alarm can be gener- ated.Access Point Station Thresholds

The following table outlines a set of thresholds, in one preferredembodiment, applied to the access point itself, and will typically besomewhat more than the Aggregate Station thresholds.

Column Description Signal Strength If the signal strength for any frameis lower than Threshold this value, an alarm can be generated. # ofAssociations Whereas stations must associate with an access per Minutepoint, access points do not associate with them- selves. Therefore, thisvalue should be zero, indicating that it does not associate. # of BytesEnter the maximum number of bytes of data per Transmitted minute thisaccess point is allowed to transmit. If a greater number is detected, analarm can be gener- ated. # of Bytes Enter the maximum number of bytesof data per Received minute this access point is allowed to receive. Ifa greater number is detected, an alarm can be gener- ated. # of DataFrames Enter the maximum number of data frames per min- Transmitted utethis access point is allowed to transmit. If a greater number isdetected, an alarm can be gener- ated. # of Data Frames Enter themaximum number of data frames per min- Received ute this access point isallowed to receive. If a greater number is detected, an alarm can begener- ated. # of Mgmt Frames Enter the maximum number of managementframes Transmitted per minute this access point is allowed to transmit.If a greater number is detected, an alarm can be generated. # of MgmtFrames Enter the maximum number of management frames Received per minutethis access point is allowed to receive. If a greater number isdetected, an alarm can be generated. # of Ctrl Frames Enter the maximumnumber of control frames per Transmitted minute this access point isallowed to transmit. If a greater number is detected, an alarm can begener- ated. # of Ctrl Frames Enter the maximum number of control framesper Received minute this access point is allowed to receive. If agreater number is detected, an alarm can be gener- ated. # of FragmentEnter the maximum number of fragment frames per Frames Seen minute thisaccess point can see before gener- ating an alarm. # of Decrypt ErrorEnter the maximum number of decrypt error frames Frames Seen per minutethis access point can see before gener- ating an alarm.Default Threshold Information

In one preferred embodiment, whenever a new access point is detected ormanually entered, the specified default settings are applied until it ismanually customized. It is assumed that new or unauthorized accesspoints are potential hackers, so it is preferable to set the defaultthresholds fairly low.

Aggregate Station Thresholds

The table below outlines a set of thresholds that refer to the combinedstatistics for all stations in one preferred embodiment.

Column Description Signal Strength If the signal strength for anystation in the BSS as- Threshold sociated with an unknown access pointis lower than this value, an alarm can be generated. # of AssociationsWhereas stations must associate with an access point, per Minute accesspoints do not associate with themselves. There- fore, this value shouldbe zero, indicating that it does not associate. # of Associated Enterthe maximum number of stations allowed to as- Stations sociate withunknown acccss points. The number should reflect your actual stations.If a greater number is detected, an alarm can be generated. # Bytes intoBSS Enter the maximum number of bytes of data per min- from Wired Netute allowed into the BSS through unknown access points from the wiredportion of your network. If a greater number is detected, an alarm canbe generated. # Bytes from Enter the maximum number of bytes of data permin- BSS to Wired ute allowed out of the BSS through unknown access Netpoints to a wired portion of your network. If a greater number isdetected, an alarm can be generated. # Bytes between Enter the maximumnumber of bytes of data per min- Stations in BSS ute allowed to betransmitted within the BSS from all stations through unknown accesspoints. If a greater number is detected, an alarm can be generated. #Bytes from Enter the maximum number of bytes of data per min- Wired Netto ute allowed to be transmitted through unknown access Wired Net pointsfrom a wired portion of the network to another wired portion of thenetwork, using the access point as a bridge. If a greater number isdetected, an alarm can be generated. Total Data Enter the maximum numberof data frames per minute Frames Seen for all stations combined allowedto be transmitted through unknown access points. If a greater number isdetected, an alarm can be generated. Total Mgmt Enter the maximum numberof management frames per Frames Seen minute for all stations combinedallowed to be trans- mitted through unknown access points. If a greaternumber is detected, an alarm can be generated. Total Ctrl Frames Enterthe maximum number of control frames per min- Seen ute for all stationscombined allowed to be trans- mitted through unknown access points. If agreater number is detected, an alarm can be generated. Total Ad hocEnter the maximum number of ad hoc frames per min- Frames Seen ute forall stations combined allowed to be trans- mitted through unknown accesspoints. If a greater number is detected, an alarm can be generated.Individual Station Thresholds

The set of thresholds outlined in the table below apply to anyindividual station in one preferred embodiment, and will typically belower than the Aggregate Station thresholds.

Column Description Signal Strength If the signal strength for anystation associated Threshold with an unknown access point is lower thanthis value, an alarm can be generated. # of Associations Enter themaximum number of associations per min- per Minute ute any station isallowed to make with an unknown access point. If a greater number isdetected, an alarm can be generated. # of Bytes Enter the maximum numberof bytes of data per Transmitted minute any station is allowed transmitthrough unknown access points. If a greater number is detected, an alarmcan be generated. # of Bytes Enter the maximum number of bytes of dataper Received minute any station is allowed to receive through unknownaccess points. If a greater number is de- tected, an alarm can begenerated. # of Data Frames Enter the maximum number of data frames permin- Transmitted ute any station is allowed to transmit through un-known access points. If a greater number is de- tected, an alarm can begenerated. # of Data Frames Enter the maximum number of data frames permin- Received ute any station is allowed to receive through un- knownaccess points. If a greater number is de- tected, an alarm can begenerated. # of Mgmt Frames Enter the maximum number of managementframes Transmitted per minute any station is allowed to transmit throughunknown access points. If a greater number is detected, an alarm can begenerated. # of Mgmt Frames Enter the maximum number of managementframes Received per minute any station is allowed to receive throughunknown access points. If a greater number is de- tected, an alarm canbe generated. # of Ctrl Frames Enter the maximum number of controlframes per Transmitted minute any station is allowed to transmit throughunknown access points. If a greater number is de- tected, an alarm canbe generated. # of Ctrl Frames Enter the maximum number of controlframes per Received minute any station is allowed to receive throughunknown access points. If a greater number is de- tected, an alarm canbe generated. # of Fragment Enter the maximum number of fragment framesper Frames Seen minute from any station that are allowed. If a greaternumber is detected, an alarm can be gener- ated. # of Decrypt ErrorEnter the maximum number of decrypt error frames Frames Seen per minutefrom any station that are allowed. If a greater number is detected, analarm can be gener- ated.

Access Point Station Thresholds

The set of thresholds in the table below applies to all unauthorizedaccess points in one preferred embodiment.

Column Description Signal Strength If the signal strength for any accesspoint is lower Threshold than this value, an alarm can be generated. #of Associations Enter the maximum number of associations per min- perMinute ute between any access point and stations. (It is recommendedthat this value not be higher than twice the number of stations in yourBSS.) # of Bytes Enter the maximum number of bytes of data perTransmitted minute allowed to be transmitted from any access point. If agreater number is detected, an alarm can be generated. # of Bytes Enterthe maximum number of bytes of data per Received minute allowed to bereceived by any access point. If a greater number is detected, an alarmcan be generated. # of Data Frames Enter the maximum number of dataframes per min- Transmitted ute allowed to be transmitted by any Accesspoint. If a greater number is detected, an alarm can be generated. # ofData Frames Enter the maximum number of data frames per min- Receivedute allowed to be received by any access point. If a greater number isdetected, an alarm can be gener- ated. # of Mgmt Frames Enter themaximum number of management frames Transmitted per minute allowed to betransmitted by any access point. If a greater number is detected, analarm can be generated. # of Mgmt Frames Enter the maximum number ofmanagement frames Received per minute allowed to be received by anyaccess point. If a greater number is detected, an alarm can begenerated. # of Ctrl Frames Enter the maximum number of control framesper Transmitted minute allowed to be transmitted by any access point. Ifa greater number is detected, an alarm can be generated. # of CtrlFrames Enter the maximum number of control frames per Received minuteallowed to be received by any access point. If a greater number isdetected, an alarm can be generated. # of Fragment Enter the maximumnumber of fragment frames per Frames Seen minute allowed for any accesspoint. If a greater number is detected, an alarm can be generated. # ofDecrypt Error Enter the maximum number of decrypt error frames FramesSeen per minute allowed for any access point. If a greater number isdetected, an alarm can be generated.

Some embodiments may allow for self-configuration of some or all of thethresholds discussed above. Such self-configuration could occur througha learning mode in which the systems and methods according o the presentinvention monitor traffic on the wireless computer network for the firstseveral hours or days after installation. In such a learning mode, alarmnotifications can be disabled. It is expected that, in the beginning,the generation of alarms will be very high—hundreds or thousands per daydepending on actual network traffic—until thresholds in accordance withthe network's normal activity. Once an accurate picture of normalnetwork traffic has been captured, and thresholds are reflective ofnormal activity, a switch to normal operations mode enables alarmnotifications.

In one preferred embodiment, a command line interface is provided toconfigure settings that are not available within the graphical userinterface. For example, the IP address of the a hardware component canbe changed, its system clock reset or set to “sync” with a network timeserver. In other embodiments, the graphical user interface and/or thecommand line interface can allow significant overlap of configurationcapability. Further, some embodiments have only one or the otherinterface type. Finally, some embodiments provide no interactiveinterface for configuration and are limited to reading configurationdata from a file, deriving configuration data from past monitoring ofthe wireless computer network or otherwise receiving this data. Thecommand line interface in one preferred embodiment can be accessedeither on the hardware component such as through a command shell such asthe Linux Gnome Terminal or over the network using an SSH (preferably,version 2) client.

In one preferred embodiment, a command shell automatically opens on thehardware component after booting. A terminal icon can appear on the taskbar at the bottom of the display; clicking the icon opens additionalterminal windows. At the command line prompt, a command is entered tolaunch the command line interface.

An SSH client is launched and connected to the hardware component's IPaddress. The identity of the user making the connection is verified. Atthe command line prompt, enter the following command to launch thecommand line interface:

Command Line Interface

In one preferred embodiment, the screen displays in the terminal windowprovide five “program areas”:

-   -   Network—offering options to change IP address, DNS servers,        hostname, domain name, mail server, ARP, and create “allow” and        “deny” lists.    -   Date—allowing time and date editing, time zone setting, and        configuration of an NTP server.    -   Service—providing tools to fine-tune the hardware component        parameters, configure data management, and reboot and shut down        the component.    -   Users—allowing creation, editing, and deletion of user accounts        allowed access to the graphical user interface.    -   Help—tips on using the application, and detailed help topics.        Network

Opening the network settings program area, the following commands areavailable in one preferred embodiment:

Command Description IP IP address config Allows modification of the IPaddress, Subnet mask, and de- fault gateway for the hardware componentlogged onto. The “IP configuration” screen opens, displaying the currentnetwork configuration and allows modification. DNS Define DNS serversAdding or deleting a DNS nameserver. The “Nameserver screen” opens,displaying your current DNS server's IP address and allows addition,deletion and modifi- cation. Note: Multiple DNS servers can in someembodiments have an “order” for processing DNS requests. The firstserver on the list (identified by the numeral 1) is the first to offername resolution; the second server on the list (identified by thenumeral 2) is the second to process the request if the first is unableto do so. In order to change the order preference of multiple servers,all must be deleted and re-entered in the de- sired order for them toprocess DNS requests. HNAME Set hostname Changing the name of thehardware component. The Hostname screen displays your current hostnameand allows modification. Bear in mind that whenever the hostname ischanged, its name must also be modified in all devices that refer to it(e.g., DNS servers). DNAME Set domain name Changing the domain to whichthe hardware component be- longs. The Domain name screen displays yourcurrent domain name and allows modification. Bear in mind that wheneverthe domain name is changed, it must also be modified in all devices thatrefer to it (e.g., DNS servers). MRELAY Config mail relay hostConfiguring a hardware component to send alarms by email. The Mail relayhost screen appears and allows entry of quali- fied hostnames. In oneembodiment, mail relay hosts may be referred to by IP address or fullyqualified hostname (e.g., myhostname.mydomainname.com) of a mail serverto process email alarm messages. Note: the mail server must beconfigured to allow this appli- ance to relay email through it, or atleast to direct its mail to another mail server that will relay it. ARPConfig permanent ARP table Creating a permanent ARP table. The ARP tablescreen dis- plays your current ARP records and allows modification. Inorder to protect connections between this hardware com- ponent andremote administrators from being hijacked by man-in-the-middle ARP“blasts” (that redirect traffic for this IP address to an alternate MACaddress), it is preferable to create permanent ARP records for gatewaysand other impor- tant machines. HALLOW Configure/etc/hosts.allow fileSpecifying which machines are allowed to connect to the hardwarecomponent. The Allow list screen displays your current list of allowedmachines and allows modification. Machines allowed to connect to thishardware components can be specified. Only those whose IP address,subnet, fully qualified hostname, or domain name match an entry in thislist are allowed to connect to this hardware component to run theavailable administrative programs and routines. HDENYConfig/etc/host.deny file Identifying machines that may not connect tothe hardware component. The Deny list screen displays your current listof denied machines and allows modification. Machines not allowed toconnect to this hardware component can be specified. Anyone whose IPaddress, subnet, fully qualified hostname, or domain name matches anentry in this list are not allowed to connect to this hardware componentNote: HALLOW, in one preferred embodiment, takes prec- edence overHDENY. For example, if 123.456.789.963 is on the allow list, yet thesubnet 123.456.789. is on the deny list, the individual machine above isallowed to connect to the appliance.Date

Opening the date settings program area, the following commands areavailable in one preferred embodiment:

Command Description TIME Time/Date config Allows configuration of thetime/date for the hardware com- ponent. TZ Set time zone Allowsconfiguration of the time zone for the hardware com- ponent. NTPEnable/disable NTP Allows configuration of the hardware component to usea network time server. Note: If you change the system time because, forexample, you move the appliance's location from the east to west coastof the United States, you must also locate a new network time server inthe same time zone.

Services

Opening the set appliance parameters, configure data management, andrestart or shutdown the system area, the following commands areavailable in one preferred embodiment:

Command Description TUNE Tune appliance parameters Allows users tomodify some of the core values related to the environment'sfunctionality. DMGT Data management Allows users to modify how theenvironment stores its data. REBOOT Reboot system Allows gracefulrestart of the hardware component. HALT Halt system Allows gracefulshutdown of the hardware component.Users

Opening the Users program area, the following commands are available inone preferred embodiment:

Command Description NEWU Create user EDITU Edit user DELU Delete user

The functionality of these features can in one preferred embodimentmatch with like functionality provided in a standard LINUX usermanagement facility.

Various methods and functions as exhibited in various embodimentsaccording to the present invention are described above and below withrespect to network security enhancement. In some embodiments, one ormore processors within architectures of the environments as describedabove may execute the steps in such methods and provide suchfunctionality. The functionality may spread across multiple processingelements. In other embodiments, any suitable computer readable storagedevice, media or combination of devices and/or media, including primarystorage such as RAM, ROM, cache memory, etc. or secondary storage suchas magnetic media including fixed and removable disks and tapes; opticalmedia including fixed and removable disks whether read-only orread-write; paper media including punch cards and paper tape; or othersecondary storage as would be known to those skilled in the art, maystore instruction that upon execution by one or more processors causethe one or more processors to execute the steps in such methods and toprovide such functionality.

Vulnerability Assessment and Threat Identification

Vulnerability assessment is accomplished by analyzing WLAN traffic,discovering access points and workstations. The system determines howmany bytes of data stations are sending and receiving, the mean signalstrength for an entire day or the hi/low signal strength for eachminute. It can distinguish between network traffic internal to thewireless network and traffic originating from or destined to thephysical, wired-network and which stations are the largest senders andreceivers of data. The system produces broad summaries of data thatreport high, low, and mean values for a variety of traffic parameters,and detailed views that show minute-by-minute snapshots of your traffic.Traffic parameters include the breakdown of frame traffic (control,management, data, and error frames) and network routing information. Thesystem determines if any traffic has not been encrypted, users areauthenticated, and all hardware is properly configured. The systemdetects rogue deployments by identifying and locating unauthorized WLANsand ad hoc networks (peer-to-peer networks) that violate company policyand jeopardize security. The system identifies suspicious WLAN trafficacross unauthorized channels and frequencies, which can be a common signof intruders accessing your WLAN or employees abusing their networkprivileges.

The systems and methods according to one preferred embodiment use anaudit of existing wireless hardware and perform a survey the air spacesurrounding the wireless network prior to activating intrusiondetection. In this way, a baseline activity level can be determined.

Step 1: Hardware Audit

Identify every access point in the wireless computer network. Obtain ordetermine for each its MAC address, Extended Service Set name,manufacturer, supported transmission rates, authentication modes, andwhether or not it is configured to run Wired Equivalent Privacy (WEP)and wireless administrative management. In addition, identify everyworkstation equipped with a wireless network interface card, and recordthe MAC address of each device. Take note of any physical features inthe environment (walls, competing electronic devices such as microwaveovens, cordless phones, etc.) that might interfere with wirelesssignals.

The hardware audit serve as the baseline against which the systems andmethods according to the present invention can compare. That is, allaccess points and wireless stations should be detected by the variousembodiments of the present invention. (If an access point or station isnot detected, follow logical troubleshooting steps.) On the other hand,it is likely that more devices than expected will be detected. Some ofthese may be stations or access points not identified or of which no onewas aware. Others may be “rogue” devices—surreptitious or unauthorizedinstallations in the network—or harmless equipment belonging to nearbycompanies, and others may be actual hackers. Once the systems andmethods according to the present invention are in intrusion detectionmode, all detected access points and stations can be reported.

Step 2: Survey Perimeter

Preferably a mobile hardware component according to the presentinvention is walked around the perimeter of the wireless computernetwork in a powered up state (allowing it to collect data as it ismoved), or placed in a central location for 12 to 24 hours to collect alarger amount of data. The benefit of a “walk-around” survey is that itgenerates a nearly immediate picture of the existing wireless “airspace.” The benefit of a “stationary” survey is that over a longerperiod of time, is greater certainty of detecting devices that onlyoperate intermittently or hackers attempting to penetrate the networkoff-hours. Repetition of the survey, whether walking or stationary,should occur on all 11 channels.

Stationary Data Collection

Depending on the size of the wireless network, a hardware component canbe placed at the four corners or at intermediate points in the ExtendedService Set footprint. At each location, the component should be allowedto passively monitor network traffic for 12–24 hours. Hard copy ofnetwork data should be preserved prior to each move.

Walk-Around Data Collection

Simply walk around the perimeter of the wireless network with thehardware component powered on and open to an overview screen. Thevarious access points and stations within the wireless computer networkcan be detected. Compare this information with the hardware audit madeprior to collecting this data. Repeat this walk-around survey for eachof the eleven channels.

Step 3: Configure to “Recognize ” this Network

Each access point detected should be designated as authorized orunauthorized. Each observed station should be designated as valid ornot.

Step 4: Place Hardware Components in Discrete Locations throughout theWireless Network

Leave a component in each location from 1–3 days. Each day, printreports to preserve captured information. Based upon this information,specific access point and station related thresholds can be tuned todistinguish between normal and abnormal traffic patterns.

The intrusion detection system (IDS) engine listens to wireless networktraffic. FIG. 3 depicts one preferred process the IDS follows inevaluating data associated with received traffic. In the depictedexemplary process, all packets pass through four detections systems:signature-based testing, protocol-based testing, anomaly-based testing,and policy deviation-based testing; other embodiments may use one ormore of these tests, or other tests, in varying combinations.

Initially, configuration information is received in step 305, typicallyincluding network default data and risk criteria. This information canbe retrieved from a file, derived or obtained from monitoring thenetwork and/or entered interactively at the outset of the process. The,system reads or receives frames from the wireless network instep 310.The received frames are interrogated as follows.

The information within the frame is interrogated to determine if a knownattack signature has been identified in step 325. Signatures encodedatalink layer attack patters as combinations of packet sequences andstate. For example, active probing emits a pattern or sequence ofnetwork requests. This sequence can be recognized by its packet sequencesignature. If the attack signature is identified, the intrusiondetection system signals an alarm manager to deliver an alert to theadministrator in step 345.

If no attack signature is identified, the frame information is passedthrough a protocol violation engine to determine if the protocol used inthe frame is authorized in step 330. Protocol analysis examines whetheror not protocol usage is legitimate. For example, emitting a largenumber of association or disassociation requests in a short interval isnot a legitimate use of the protocol. If the protocol used in the frameis outside of the authorized protocol set, the intrusion detectionsystem signals an alarm manager to deliver an alert to the administratorin step 345.

If the protocol test passes, in step 335, the IDS checks the frame datafor statistical anomalies against the SDS, or a statistics databasemaintained therein. Anomaly based detection computes such values as themean, non-zero mean, standard deviation, autocorrelation and peak foreach time slice throughout the day. This can be used to create anormalized statistics database for each time slice and user. Currentactivity is then monitored and compared with the recorded statisticsvector. If the difference is larger than a configurable threshold, analert is generated. Instead of, or in addition to, this approach, aBayes test can be applied to deduce the probability that the currentstatistics vector is an attack as opposed to a legitimate sequence. Ifan anomaly exists, the intrusion detection system signals an alarmmanager to deliver an alert to the administrator in step 345.

If no anomaly is detected, the system interrogates the frame todetermine if a pre-defined policy has been violated in step 340. Policytesting compares the observed activity with a configurable set ofactivity rules stored in the SDS. For example, a rule can declare thatonly specific hosts with specific addresses and specific network cardscan access the network. If a pre-defined policy has been violated, theintrusion detection system signals an alarm manager to deliver an alertto the administrator in step 345.

The tests outlined above and depicted in FIG. 3 are performed serially.In other embodiments, one or more of these tests may occur in parallel.Further, subsequent tests only occur if a prior test was passed. In afurther preferred embodiment, all tests occur irrespective of theoutcome of a prior test; consequently, a single read frame couldpotentially generate an alarm for every test performed on it.

Alerts can be in the any suitable form delivered to any suitableplatform including, without limitation, a screen display to a monitor, apage to a pager, an outgoing voice call to telephone, a SMS message to amobile telephone, an e-mail message to a valid address, posted to a Webpage available via an appropriate Web server or WAP alert to a WAPenabled device. Various types of screen displays and reports may be usedto provide information regarding generated alarms.

In one preferred embodiment referred to as AirDefense Mobile in U.S.Provisional Patent Application Serial Number TBA entitled “SYSTEMS ANDMETHODS FOR NEWTORK SECURITY” filed May 20, 2002 bearing Ser. No.10/161,142, preferred interfaces for reviewing and reporting alarms aredescribed in detail. The contents of this application are herebyincorporated by this reference herein for all purposes.

In some embodiment, the outputs of all IDS test are then compared and aconfidence level computed in step 345. In one such embodiment, in thecase where only a statistical anomaly is detected, it is flagged as alower level performance alert. In the case where one or more otherviolations are detected, the alarm is elevated to an intrusion alarm.

Some embodiments may use a variety of data stores in implementing theabove process to track data across multiple iterations of the process;such data stores can in one preferred embodiment be part of an SDS asdescribed above. Some such embodiments can include a statisticsdatabase, a station database and/or a state data store. In suchembodiments, some or all of the following steps depicted in FIG. 3 canoccur.

In step 315, a station database is updated. This database contains, inone preferred embodiment, per station and per access point records withinformation describing device address, communications state, timestampsof first and last activity, counts of byte transmissions and localpolicy information describing whether device is authorized or not forusage in the monitored network.

In step 320 state information is updated. State refers to whether or notthe device has been seen before and whether or not the station isunauthenticated and unassociated, authenticated, authenticated andassociated or unknown state information associated with the wirelesscomputer network.

In step 350, a determination is made as to whether a particularstatistics interval has been complete. If so, statistics in an SDS areupdated in step 355, and processing continues with the next frame instep 310. Otherwise, processing simply continues in step 310 with thenext reading or receiving of a frame.

A modified and enhance version of the above approach is used wherenetwork traffic is monitored from multiple input devices such as withthe embodiments depicted in FIGS. 2B–E. FIG. 4 depicts this enhancedprocess starting at step 405.

Step 410 is analogous to step 305 from the process of FIG. 3. In step410, configuration information is received. As before, this is typicallydone through reading system configuration files, monitoring the networkand/or interactive entry at the outset of the process. This informationtypically includes network default data and risk criteria such as accesspoint configuration data (MAC Address of the access point, Access PointName, etc.), station configuration data and various thresholds values.

In step 430, a wireless packet frame is received from each input device(e.g., hardware components 210A–D, host system 220 and/or sensors 230A,230B). Frames are read so that the frame content can be interrogated.

Each read frame is interrogated by a multi-dimensional intrusiondetection system (IDS) such as detailed above with respect to FIG. 3,and the outputs of all IDS tests are then compared and a confidencelevel computed in step 435. As with the process above, other tests ineither alone, in combination with each other or in combination with oneor more of those described above may be used in other embodiments.

In step 440, in the case where only a statistical anomaly is detected,it is flagged as a lower level performance alert. In the case where, inaddition to the statistical anomaly, one of the other violations hasbeen detected, the alarm is elevated to an intrusion alarm and an alarmmanger is alerted in step 444. Other embodiments do not rely onaggregate test outcome but determine alarm status on single testoutcomes. Further, some embodiments can use other test types and outcomecombinations to determine type and severity of alarms generated.

If an alarm is not detected in step 440, a test to see if apredetermined interval for gathering statistics has been reached occursin step 460. If the end of the pre-configured statistics gatheringinterval has occurred, the SDS is updated in step 470 to reflect thestatistics gathered from the received frames over the interval.Statistics are gathered by monitoring traffic between network nodes,minute-by-minute statistics about BSS frame types and traffic volumes,summaries of transmission statistics for all stations associated withaccess points, current-minute transmission statistics for all Stations,and detailed minute-by-minute transmission statistics for any individualstation in the wireless computer network.

Data fusion occurs on a batch basis by aggregating data from multipledatabases. This process begins at step 414. The process integratesstatistical data from multiple databases that is generated through framemonitoring and intrusion detection engines. This approach provides amethodology for managing data received from input devices such ashardware devices 210A–D and/or sensors 230A, 230B deployed at multiplesites and for aggregating enterprise data at a single central systemsuch as host 220.

The Attack and Station Profile database is read at step 418 to begin aprocessing loop to integrate databases from separate sources.Correlation and pattern recognition is performed at step 420 to updatethe attack and station profiles in step 424. The processing loop thensleeps at step 428 until the next processing loop interval is to takeplace based on the pre-configured time interval or trigger.

After the alarm manager is signaled in step 444, the attack and stationprofile database is read in step 448; in this step, existing attacks arequeried and existing station security state is queried. In step 450,this data is compared to the newly generated alarm. If it issufficiently similar, no new external notification occurs in step 454.If it is not, a new notification message is generated in step 454 andconsole display and/or external messaging of the alarm occurs in step458.

As described above, systems and methods according to the presentinvention can automatically generate alarms whenever certain events orconditions occur within your wireless network. In some embodiments, analarm manager providing an interface for viewing can be provided; suchan interface is described in greater detail in co-pending “SYSTEMS ANDMETHODS FOR NEWTORK SECURITY” filed May 20, 2002 bearing Ser. No.10/161,142. The following table identifies the alarms, alarm subtypesand severities available in one preferred embodiment referred to asAirDefense Mobile.

Alarm Alarm Type Alarm Subtype Level DoS Attack De-authenticate CriticalAirDefense Mobile detects when a hacker pretends to be an Access pointand broad- casts a “de-authenticate” message. This forces all Stationsto re-authenticate them- selves, generating excessive network traf- fic,and causing inconsistent connectivity, and data transfer. DisassociateCritical AirDefense Mobile detects when a hacker pre- tends to be anAccess point and broadcasts a “disassociate” message. This forces allStations to re-associate themselves with the Access Point, generatingexcessive network traffic, and causing inconsistent connectivity anddata transfer. Unauthorized Not on allow list Critical StationAirDefense Mobile detects a Station whose MAC address is not on itsValid list. (A Valid list is maintained by the system.) Threshold GLBCRC errors Major AirDefense Mobile detects if CRC errors ex- ceededconfigured limits (CRC errors are generated when checksums fail onindivid- ual frames.) BSS assoc count Major AirDefense Mobile detectswhen the number of associations within an entire BSS, in any givenminute, exceed the number specified in con- figuration information BSSsignal strength Critical AirDefense Mobile detects when the signalstrength in any access point falls below a specified threshold. BSSfragments Minor AirDefense Mobile detects when the number of fragmentedframes within any minute exceed a specified threshold. BSS decrypterrors Major AirDefense Mobile detects when the number of decrypt errorframes within any minute ex- ceed a specified threshold. BSS assocstations Minor AirDefense Mobile detects when the total num- ber ofassociated Stations within an entire BSS, in any given minute, exceed aspecified number. BSS tbw in Minor AirDefense Mobile detects when,during any minute, the number of bytes of data entering the BSS from thewired portion of your net- work exceed a set threshold. BSS tbw outMinor AirDefense Mobile detects when, during any minute, the totalnumber of bytes of data going from the BSS to a wired portion of yournetwork exceed a set threshold. BSS tbw intra Minor AirDefense Mobiledetects when, during any minute, the total number of bytes of dataoriginating from and destined for the BSS exceed a specified threshold.BSS tbw thru Minor AirDefense Mobile detects when, during any minute,the total number of bytes of data originating from a wired portion ofthe net- work hop through the BSS to another wired portion of thenetwork exceed a set threshold. BSS data Major AirDefense Mobile detectswhen, during any minute, the total number of data frames in the BSSexceed a specified threshold. BSS mgt Major AirDefense Mobile detectswhen, during any minute, the total number of management frames in theBSS exceed a specified threshold. BSS ctl Major AirDefense Mobiledetects when, during any minute, the total number of control frames inthe BSS exceed a set threshold. BSS ad hoc Critical AirDefense Mobiledetects when, during any minute, the total number of Ad Hoc frames inthe BSS exceed a specified threshold. Note: Wireless network adaptorcards of lesser quality will randomly generate Ad Hoc frames. AirDefenseMobile's default threshold (1) may cause all of these spurious frames togen- erate an alarm. After monitoring the network for a week or two, itmay be advisable to set the threshold to a number at or a little higherthan what the network normally generates. STA assoc count MajorAirDefense Mobile detects, during any minute, when any Stationassociates with an access point more times than provided by a specifiedthreshold. STA signal strength Critical AirDefense Mobile detects,during any minute, when any station's signal strength falls below avalue specified. STA fragments Minor AirDefense Mobile detects, duringany minute, when any station generates more fragmented frames than aspecified value. STA decrypt errors Major AirDefense Mobile detects,during any minute, when any station generates more decrypt errors than aset threshold. STA tbw received Minor AirDefense Mobile detects, withinany minute, when any station receives more bytes of data than apredetermined threshold. STA tbw transmitted Minor AirDefense Mobiledetects, within any minute, when any station transmits more bytes ofdata than specified in a set threshold. STA data received MajorAirDefense Mobile detects, within any minute, when any station receivesmore data frames than a specified threshold. STA data transmitted MajorAirDefense Mobile detects, within any minute, when any station transmitsmore data frames than a specified threshold. STA mgt received MajorAirDefense Mobile detects, within any minute, when any station receivesmore management frames than a specified threshold. STA mgt transmittedMajor AirDefense Mobile detects, within any minute, when any stationtransmits more management frames than a set threshold. STA ctl receiveMajor AirDefense Mobile detects, within any minute, when any stationreceives more control frames than a specified threshold. STA ctltransmit Major AirDefense Mobile detects, within any minute, when anystation transmits more control frames than a set threshold. ID Theft Outof sequence Critical AirDefense Mobile detects when frames aretransmitted out of sequence. This suggests that someone has spoofed aStation and is sending data at the same time as the legitimate Station.Vendor out of character Critical AirDefense Mobile compares everyStation's transmissions against an internal database of known vendor“transmission profiles” or “signatures.” If the actual network trafficdoes not match the vendor-profile associated with the Station's WirelessNIC, AirDefense Mobile assumes that the traffic originates from anunauthorized station using a spoofed NIC. Anomalous signal strengthCritical AirDefense Mobile tracks the high, low, and mean signalstrength of each station many times a minute throughout the day.Whenever it detects that the Station's signal strength deviates from thenorm, it generates an alarm. Access Point WEP mode changed Critical ModeAirDefense Mobile detects when the WEP value in an access point's beacondiffers from the value it is supposed to be. (AirDefense Mobileauto-detected the WEP property, or it was manually entered.) Ratechanged Critical AirDefense Mobile detects when the supportedtransmission rate values in an access point's beacon differs from thevalue it is supposed to be. (AirDefense Mobile auto-detected the rateproperty, or it was manually entered.) Channel changed CriticalAirDefense Mobile detects whenever an access point changes channels.(The channel is iden- tified in configuration information.) Cf changedAirDefense Mobile detects when the Point Coordination value in an AP'sbeacon changes. A change in this field may indicate that the accesspoint was reconfigured, though this is not necessarily a problem. (ThePoint Coordi- nation field refers to the access point's mode ofcollision avoidance.) Essid changed AirDefense Mobile detects when theaccess point's broadcast of its Extended BSS ID changes. The ESSIDinformation is stored as configuration information. UnauthorizedAirDefense Mobile detects when administration Critical AP Admin sessionsare being conducted directly with the access point. Odd Mgt. Sta tx apmgt fr Critical Frame AirDefense Mobile detects when a Station istransmitting a management frame reserved for access point's use. Ap txillegal mgt fr Critical AirDefense Mobile detects when an access pointtransmits an illegal management frame. Out of spec frame CriticalAirDefense Mobile detects when an access point transmits a frame thatdoes not follow 802.11b standards. Other bogus frame Critical AirDefenseMobile detects when an access point transmits any frame it does notunder- stand. Ad Hoc Net AirDefense Mobile detects when Stations areCritical Detected directly transmitting and receiving to and from eachother without using an authorized access point. Note: Unlike all otheralarms that are gener- ated every time the network event is detectedwithin a minute, AirDefense Mobile will only generate an Ad Hoc Networkalarm once in the current 24 hour period for each MAC address. AP BeaconAirDefense Mobile detects when an access Critical Rate point's beaconrate changed.Active Defense

In some embodiments of the present invention, one or more active defensemechanisms may be triggered in response to alarm in addition to, orinstead of, the notification process described above. The system mayprovide active defense from attacks by broadcasting data into thewireless network as well as being able to trap and/or map an intruder'sworkstation by triangulating the position of the intruder's workstationrelative to the wireless network access points.

By introducing CRC errors into the wireless stream, the system canactively defeat an attacker that is monitoring the stream for patternsto crack the encryption. CRC errors are introduced by transmitting atthe same time as the detected intruder.

Due the shared medium nature of the wireless computer network, the causethe packet transmission to be corrupted, preventing the intruder fromsuccessfully communicating with the network.

By introducing chaf, the system can actively defeat the attacker byplacing random frames into the stream so that the encryption patternbecomes undetectable. Chaf is a form of randomized packet transmissionthat is designed to reduce the probability that a statistical analysisof the packet sequence would result in breaking of the encryption key.This is done by emitting a low-rate background transmission of packetsthat are emitted using the same characteristics (e.g., address,initialization vector, etc.) of legitimately observed traffic but with arandomized payload.

The system can lock-down a wireless network by jamming, a technique toprevent any unauthorized access to the wireless access point byintroducing enough noise into the wireless network that workstationscannot physically connect to the wireless network. Jamming is a physicallayer transmission that is performed to disrupt all unwanted wirelesscommunications. It is equivalent to introducing a noise signal on top ofthe unwanted signal transmission such that any receiver would not beable to successfully receive the transmission.

In a Physical Device approachOne embodiment would utilize a standalonesensor to implement any of the Active Defense mechanisms. Dynamicchannel change can be used to reroute authorized traffic to a differentcommunication channel to avoid an intruder detected on a particularchannel. In this approach, a channel change request is transmitted tothe access point believed to be compromised and authorized stations usethe new channel to communicate with the access point. This approach canalso be used to avoid interference causing problems in communicationbetween an access point and its authorized stations.

Some embodiments including dynamic channel change may further use ahoneypot trap that tricks the attacker into thinking the originalchannel is still valid and provides the necessary forensic informationto identify the attacker. FIG. 5 depicts a flow chart of a processstarting at step 510 used in some such embodiment incorporating thehoneypot trap.

In step 520, configuration information is received. This step is muchthe same as previously described steps 305 and 410 in FIGS. 3 and 4respectively. Step 530 represents a waiting loop that waits until anattack has been detected. Typically, an intrusion detection systemgenerates a signal that triggers departure from this loop; in somepreferred embodiments, the intrusion detection system contains thehardware and/or executes the process described above. The signal fromthe intrusion detection system typically includes an indicator of theaccess point believed to be under attack.

In the case that an attack has been detected in 530, processing ispassed to step 540 to activate the honeypot trap. A trap thread isstarted in step 580; the thread initializes itself with the identity ofthe monitored access point believed to be attacked. This identitytypically includes the MAC address, Service Set Identifier, encryptionmode, network mode and transmission modes. Once initialized, the threadmoves to step 590, the Trap Intruder process. This process is designedto logically fool the identifier attacker into believing communicationis still occurring with the original access point. This is accomplishedthrough complete emulation of the original access point's identity andbehavior. By maintaining communication with the attacker, a trap iscreated such that the attacker's physical proximity is assured as longas communication continues. Optionally, a new identity may be assumedsuch that a weaker or more vulnerable appearing access point can bepresented to the attacker. This is done by again emulating access pointfunctionality, but in this case with an identity and set ofcharacteristics that appear vulnerable. This vulnerability appearancemay be created through the use of no or weak encryption modes or theappearance of default manufacturing modes with known passwords and userIDs.

In step 550 a control packet is sent to the original access point tochange channels or suspend transmission while the trap is engaged. Thispacket encapsulates a message indicating the above request and may besent in or out-of-band to the access point. In-band refers toover-the-air transmission to the access point's wireless networkinterface whereas out-of-band transmission refers to transmission to thewired side interface of the access point.

Processing in the main loop then returns to attack detection in 530.

Triangulation determines the location of an attacker by mapping herrelative position within the deployed wireless access points. Themapping and location detection process according to one or morepreferred embodiments of the present invention as depicted in FIGS. 6A–Bare discussed in greater detail below.

The process of FIG. 6A is used to create an internal database of IPaddresses and/or names mapped to corresponding MAC addresses. EveryAddress Resolution Protocol (ARP) transaction is detected in step 605.In step 610, the information in the detected transaction is used toupdate the internal database. Some embodiments can perform theidentification and location processing such as depicted in FIG. 6Bwithout reference to such an internal database. This database is createdand maintained in one preferred embodiment to make the stationidentification and location process easier and more efficient.

FIG. 6B depicts a process for identifying and locating a station withinthe wireless network. In some embodiments, this process can be used topinpoint the location of a potential attacker, in some such embodiments,activation of the process is triggered by an intrusion detection system.In a preferred embodiment, the process is triggered by one of theintrusion detections systems and methods described in detail above.

In step 620, a lookup occurs in the internal database, such as createdvia the process depicted in FIG. 6A, on the current MAC address todetermine if an IP or name mapping is already available. If found, theinternal database is updated in step 640 and execution proceeds to step645 to query the wireless sensor array, to begin position or locationresolution. As indicated above, the internal database is one approach toacquiring the desired information. Some embodiments may skip this stepand use either the wired network sensor or the reverse addressresolution protocol (RARP) approach discussed below.

Otherwise, an optional wired network sensor can be queried for the namemapping in step 625. This sensor is preferably deployed within the wirednetwork at a location convenient to sniffing DHCP, LDAP, DNS or otherservice/name mapping protocols. If found, the internal database isupdated in step 640 and execution proceeds to step 645 to query thewireless sensor array, to begin position or location resolution. Someembodiments may not include such a wired network sensor; in which casethis step is skipped.

If name is still not found, execution proceeds to step 630 where a RARPrequest is issued. This request asks the receiver population for the IPaddress of the MAC address in question. If found, the internal databaseis updated in step 640 and execution proceeds to step 645 to query thewireless sensor array, to begin position or location resolution.

If not found, name/IP mapping is not available at current time for thisMAC address. In some embodiments, name/IP mapping may not be desired butlocation or position information is in which case the process can beginin such embodiments at step 645.

Step 645 begins the position or location resolution with a query to thewireless sensor array. Each sensor is queried for tracking informationon the current MAC address in question. This tracking informationidentifies whether the MAC is currently observable by a given sensor,the sensor ID, and the signal strength associated with the MAC inquestion. The sensor array may include not only sensor devices (e.g.,230A, 230B) but also other wireless nodes accessible from this processsuch as devices 210A–D and/or host system 220.

From the data received via the query, the position relative to grid ofsensors is calculated in step 650 by computing the “signal strength”distance to each sensor. This distance is computed as the square root ofthe sum of squares of three sensor signal strength values. The positionis then estimated to be within the proximity of the sensors determinedto have the smallest signal strength distance to the MAC address inquestion per the above computation. Once the set of sensors is selected,the position is further refined by selected the position as within theproximity of the sensor within above set with the strongest signalstrength. In some embodiments, the process ends at this point with theposition information being returned.

In embodiments maintaining a position database, this database is updatedin step 660 with the position of the MAC address in question. Theprocess then ends at step 670.

Encrypted Network Analysis and Management

The techniques utilized to monitor WLANs can apply in general tomonitoring and analyzing any network link using encryption of thepayload or at the IP layer and above rather than just WLANs. In thiscase, Layer 1 and Layer 2 are observed and decisions made at theselayers in terms of signature, protocol, policy and statistical anomalyanalysis to assess network health and security. This technique is thusapplicable to any network (wired or wireless) exhibiting the aboveencryption characteristics of the network traffic. In other words, themulti-dimensional IDS implemented per our framework is more broadlyapplicable to managing and securing any encrypted network. In this case,a WLAN running WEP is one particular instance of an encrypted network.

Throughout this application, various publications may have beenreferenced. The disclosures of these publications in their entiretiesare hereby incorporated by reference into this application in order tomore fully describe the state of the art to which this inventionpertains.

The embodiments described above are given as illustrative examples only.It will be readily appreciated by those skilled in the art that manydeviations may be made from the specific embodiments disclosed in thisspecification without departing from the invention. Accordingly, thescope of the invention is to be determined by the claims below ratherthan being limited to the specifically described embodiments above.

1. A network security system, the system comprising: a) a system datastore capable of storing network default and configuration data; b) awireless transmitter capable of transmitting communications over awireless computer network; c) a system processor comprising one or moreprocessing elements, wherein the system processor is in communicationwith the system data store and the wireless transmitter and wherein thesystem processor is programmed or adapted to perform the stepscomprising of: i) receiving an active defense request signal, whereinthe request signal comprises an indicator corresponding to a potentiallycompromised access point in the wireless computer network; and ii)responsive to the received request signal, triggering one or more of thefollowing defensive actions: 1) transmitting a signal via the wirelesstransmitter to jam communications targeted at the potentiallycompromised access point; 2) transmitting a signal via the wirelesstransmitter to corrupt communications targeted at the potentiallycompromised access point by introducing CRC errors; 3) transmitting asignal via the wireless transmitter to increase difficulty associatedwith breaking of encryption associated with the wireless computernetwork and the potentially compromised access point, wherein the signalincludes packets emulating legitimate traffic but with randomizedpayloads; or 4) transmitting a channel change request communication viathe wireless transmitter to the potentially compromised access point. 2.The system of claim 1, wherein the system processor is furtherprogrammed or adapted to perform the steps comprising of receivingconfiguration information and storing the received configurationinformation in the system data store.
 3. The system of claim 2, whereinthe configuration information is received by the system processor from aconfiguration file, from an interactive data entry interface or from acommand line.
 4. The system of claim 2, wherein the receivedconfiguration information comprises network default data.
 5. The systemof claim 2, further comprising a wireless receiver capable of receivingcommunications transmitted over the wireless computer network andwherein the system processor is programmed or adapted to monitor thewireless computer network using the wireless receiver as part of itsprogramming or adaptation to receive configuration information.
 6. Thesystem of claim 1, wherein the system processor is further programmed oradapted to perform the step comprising of notifying an administrator ofthe received request signal.
 7. The system of claim 1, wherein thesystem processor is further programmed or adapted to perform the stepcomprising of mapping station identity.
 8. The system of claim 1,wherein the system processor is further programmed or adapted to performthe step comprising of mapping station location.
 9. The system of claim1, further comprising a mounting card comprising a standard computerinterface allowing communication between components mounted thereon anda computer system and wherein at least one of the processing elements ofthe system data store and the wireless transmitter are mounted onmounting card.
 10. The system of claim 9, wherein the standard computerinterface is an ISA bus connection, an EISA bus connection, a PCMCIAconnection, a USB connection, a SCSI connection, a serial portconnection or a parallel port connection.
 11. The system of claim 1,further comprising a wireless receiver capable of receivingcommunications transmitted over the wireless computer network.
 12. Thesystem of claim 11, wherein the one or more triggered defensive actionscomprises transmitting a channel change request communication andwherein the system processor is further programmed or adapted to performthe steps comprising of assuming characteristics associated with thepotentially compromised access point and emulating the potentiallycompromised access point in communicating with a potential intruder. 13.The system of claim 12, wherein the system processor is furtherprogrammed or adapted to perform the steps comprising of identifying anode associated with the potential intruder and locating the identifiednode.
 14. The system of claim 11, wherein the system processor isfurther programmed or adapted to perform the step comprising ofmonitoring the wireless computer network using the wireless receiver.15. The system of claim 14, wherein the system processor is furtherprogrammed or adapted to perform the step comprising of communicatinginformation derived from monitoring the wireless computer network to anintrusion detections system.
 16. The system of claim 15, furthercomprising a wired communication interface via which the systemprocessor communicates with the intrusion detection system.
 17. Thesystem of claim 15, further comprising the intrusion detection systemand wherein the system processor is programmed or adapted to receive theactive defense request signal from the intrusion detection system. 18.The system of claim 1, wherein the system processor is furtherprogrammed or adapted to perform the step of selecting one or moredefensive actions to be triggered.
 19. The system of claim 18, whereinthe received active defense request signal further comprises a securityindicator indicating a type of risk to the wireless computer network andwherein the system processor is further programmed or adapted to performthe step of selecting one or more defensive actions based upon thesecurity indicator in the received active defense request signal. 20.The system of claim 18, wherein the received active defense requestsignal further comprises a defense indicator corresponding to one ormore defensive actions to be triggered and wherein the system processoris further programmed or adapted to perform the step of selecting one ormore defensive actions based upon the defense indicator in the receivedactive defense request signal.
 21. A network security method, the methodcomprising the steps of: a) receiving configuration informationcomprising network configuration and default data from a configurationfile, an interactive data entry interface or a command line interface orfrom monitoring a wireless computer network; b) receiving an activedefense request signal from an intrusion detection system, wherein thereceived request signal comprises an access point indicatorcorresponding to a potentially compromised access point in the wirelesscomputer network and a risk indicator; c) responsive to the receivedrequest signal, selecting one or more defensive actions based upon thereceived request signal from the group consisting of: i) transmitting asignal to jam communications targeted at the potentially compromisedaccess point; ii) transmitting a signal to corrupt communicationstargeted at the potentially compromised access point by introducing CRCerrors; iii) transmitting a signal to increase difficulty associatedwith breaking of encryption associated with the wireless computernetwork and the potentially compromised access point, wherein the signalcomprises packets emulating legitimate traffic but with randomizedpayloads; and iv) transmitting a channel change request communication tothe potentially compromised access point; and d) triggering the selectedone or more defensive actions; and e) identifying a node or locationassociated with a potential intruder interacting with the potentiallycompromised access point.
 22. Computer readable storage media storinginstructions that upon execution by a system processor cause the systemprocessor to perform the method of claim
 21. 23. A network securitysystem, the system comprising: a) storing means for receiving andstoring configuration information comprising network configuration anddefault data; b) wireless receiving means for receiving communicationstransmitted over the wireless communication network; c) wirelesstransmitting means for transmitting communications over the wirelesscommunication network; d) defense request receiving means for receivingan active defense request signal from an intrusion detection system,wherein the received request signal comprises an access point indicatorcorresponding to a potentially compromised access point in the wirelesscomputer network and a risk indicator; e) active defense means forselecting one or more defensive actions based upon a received requestsignal received by the defense request receiving means from the groupconsisting of: i) transmitting a signal via the wireless transmittingmeans intended to jam communications targeted at the potentiallycompromised access point; ii) transmitting a signal via the wirelesstransmitting means to corrupt communications targeted at the potentiallycompromised access point by introducing CRC errors; iii) transmitting asignal via the wireless transmitting means to increase difficultyassociated with breaking of encryption associated with the wirelesscomputer network and the potentially compromised access point, whereinthe signal includes packets emulating legitimate traffic but withrandomized payloads; and iv) transmitting a channel change requestcommunication to the potentially compromised access point via thewireless transmitting means; and for triggering the selected one or moredefensive actions; and f) mapping means for identifying a node orlocation associated with a potential intruder interacting with thepotentially compromised access point.